Frank and Stephanie have an 18 year old son who is going to college this year, for four years. The tuition is $15,000 per year and is expected to increase at 4% per year. They believe they can earn 6% per year on their investment, what lump-sum amount must they deposit today, to pay for their son’s education?

a. $55,095.18

b. $56,626.37.

c. $57,222,71.

d, $58,323.15.